JP5709100B2 - Denitration device for internal combustion engine and ship - Google Patents
Denitration device for internal combustion engine and ship Download PDFInfo
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- 238000002485 combustion reaction Methods 0.000 title claims description 95
- 239000003054 catalyst Substances 0.000 claims description 190
- 238000011144 upstream manufacturing Methods 0.000 claims description 122
- WTHDKMILWLGDKL-UHFFFAOYSA-N urea;hydrate Chemical compound O.NC(N)=O WTHDKMILWLGDKL-UHFFFAOYSA-N 0.000 claims description 63
- 238000010438 heat treatment Methods 0.000 claims description 37
- 238000000605 extraction Methods 0.000 claims description 27
- 230000008929 regeneration Effects 0.000 claims description 25
- 238000011069 regeneration method Methods 0.000 claims description 25
- 230000001172 regenerating effect Effects 0.000 claims description 3
- 239000007789 gas Substances 0.000 description 102
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 56
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 36
- 239000003638 chemical reducing agent Substances 0.000 description 29
- 229910021529 ammonia Inorganic materials 0.000 description 28
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 description 23
- 229910052921 ammonium sulfate Inorganic materials 0.000 description 23
- 235000011130 ammonium sulphate Nutrition 0.000 description 23
- 230000002378 acidificating effect Effects 0.000 description 22
- 239000007787 solid Substances 0.000 description 16
- 230000006866 deterioration Effects 0.000 description 12
- 238000010586 diagram Methods 0.000 description 10
- 231100000331 toxic Toxicity 0.000 description 6
- 230000002588 toxic effect Effects 0.000 description 6
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 5
- 239000004202 carbamide Substances 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 5
- 238000006722 reduction reaction Methods 0.000 description 5
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 5
- XTQHKBHJIVJGKJ-UHFFFAOYSA-N sulfur monoxide Chemical class S=O XTQHKBHJIVJGKJ-UHFFFAOYSA-N 0.000 description 4
- 238000010531 catalytic reduction reaction Methods 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 229910052815 sulfur oxide Inorganic materials 0.000 description 3
- 229910052720 vanadium Inorganic materials 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- -1 SO 2 Chemical class 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000007062 hydrolysis Effects 0.000 description 2
- 238000006460 hydrolysis reaction Methods 0.000 description 2
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- 239000007924 injection Substances 0.000 description 2
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- 231100000419 toxicity Toxicity 0.000 description 2
- 230000001988 toxicity Effects 0.000 description 2
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 2
- 229910052721 tungsten Inorganic materials 0.000 description 2
- 239000010937 tungsten Substances 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 229910021536 Zeolite Inorganic materials 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 239000004480 active ingredient Substances 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- BIGPRXCJEDHCLP-UHFFFAOYSA-N ammonium bisulfate Chemical compound [NH4+].OS([O-])(=O)=O BIGPRXCJEDHCLP-UHFFFAOYSA-N 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- OHJMTUPIZMNBFR-UHFFFAOYSA-N biuret Chemical compound NC(=O)NC(N)=O OHJMTUPIZMNBFR-UHFFFAOYSA-N 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 1
- TXKMVPPZCYKFAC-UHFFFAOYSA-N disulfur monoxide Inorganic materials O=S=S TXKMVPPZCYKFAC-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- ZFSLODLOARCGLH-UHFFFAOYSA-N isocyanuric acid Chemical compound OC1=NC(O)=NC(O)=N1 ZFSLODLOARCGLH-UHFFFAOYSA-N 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 239000011343 solid material Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 239000010457 zeolite Substances 0.000 description 1
Landscapes
- Exhaust Gas After Treatment (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
Description
本発明は、内燃機関やガスタービン、特に船用大型低速ディーゼル機関に用いられる内燃機関用脱硝装置及びこの内燃機関用脱硝装置を搭載する船舶に関する。 The present invention relates to a denitration device for an internal combustion engine used in an internal combustion engine and a gas turbine, particularly a large low-speed diesel engine for ships, and a ship equipped with the denitration device for an internal combustion engine.
国際海事機関では、マルポール条約付属書の改正案が採択され、２０１１年からＮＯｘの規制値を現行規制値よりも１５〜22％削減することが決まっている。更に、２０１６年から指定海域においてはＮＯｘの規制値を現行規制値よりも８０％削減する方向である。
船用大型低速ディーゼル機関は、機械回転数が約７０ｒｐｍ〜１５０ｒｐｍ程度であるが、ＮＯｘの現行規制値は１７ｇ／ｋＷｈであり、２０％削減を実現するには１４ｇ／ｋＷｈ、８０％削減を実現するには３ｇ／ｋＷｈ程度にしなければならない。
The International Maritime Organization has adopted a draft amendment to the Annex of the Mar Paul Convention, and since 2011 it has been decided to reduce the NOx regulation value by 15-22% from the current regulation value. Furthermore, starting in 2016, in the designated sea area, the regulation value of NOx will be reduced by 80% from the current regulation value.
The large low-speed diesel engine for ships has a mechanical rotation speed of about 70 rpm to 150 rpm, but the current regulation value of NOx is 17 g / kWh, and in order to achieve 20% reduction, 14 g / kWh, 80% reduction is realized. In this case, it should be about 3 g / kWh.
船用大型低速ディーゼル機関における現在までのＮＯｘ削減技術としては、機関内部でＮＯｘを削減するインエンジン技術が主流であるが、数例、アンモニア水や尿素水を還元剤とした選択接触還元（ＳＣＲ）（Ｓｅｌｅｃｔｉｖｅ Ｃａｔａｌｙｔｉｃ Ｒｅｄｕｃｔｉｏｎ）法が用いられている。
アンモニア選択接触還元法では、アンモニア（ＮＨ３）を排気ガスに吹き込み、触媒によりアンモニア（ＮＨ３）と窒素酸化物ＮＯｘ（ＮＯ、ＮＯ２）を反応させ、水蒸気（Ｈ２Ｏ）と窒素（Ｎ２）に分解する方法である。
触媒には、二酸化チタン（ＴｉＯ２）を主成分として、活性成分であるバナジウム（Ｖ）やタングステン（Ｗ）などが添加されている。この種の触媒が性能を発揮する操作温度は通常３５０℃以上である。
In-engine technology that reduces NOx inside the engine is the mainstream technology to date for large-scale marine low-speed diesel engines, but several examples include selective catalytic reduction (SCR) using ammonia water or urea water as a reducing agent. (Selective Catalytic Reduction) method is used.
In the ammonia selective catalytic reduction method, ammonia (NH 3 ) is blown into exhaust gas, and ammonia (NH 3 ) and nitrogen oxides NOx (NO, NO 2 ) are reacted by a catalyst, and water vapor (H 2 O) and nitrogen (N It is a method of decomposing into 2 ).
The catalyst contains titanium dioxide (TiO 2 ) as a main component and vanadium (V) or tungsten (W) as active components. The operating temperature at which this type of catalyst exhibits performance is usually 350 ° C. or higher.
一方で、アンモニアは有毒であり、特に船舶ではその保管や扱いが困難であるために還元剤として尿素水を用いることが考えられるが、尿素水を還元剤として用いる場合には、アンモニアへの分解性や対象空間での分散性が問題となり、十分に分解しない状態では、壁面を腐食してしまう。
また、還元剤としてアンモニア又は尿素を用い、排ガス中にＳＯ２等の硫黄酸化物が含まれる場合には、反応温度が低いと酸性硫安（ＮＨ４ＨＳＯ４）が生成され、壁面や触媒表面に白い粉が付着して内燃機関の性能低下や脱硝性能が低下してしまう。
On the other hand, ammonia is toxic, and it is difficult to store and handle it on ships, so it may be possible to use urea water as a reducing agent. However, when urea water is used as a reducing agent, it is decomposed into ammonia. And dispersibility in the target space become a problem, and the wall surface is corroded if it is not sufficiently decomposed.
In addition, when ammonia or urea is used as the reducing agent and the exhaust gas contains sulfur oxides such as SO 2 , acidic ammonium sulfate (NH 4 HSO 4 ) is generated at a low reaction temperature, and is formed on the wall surface or catalyst surface. White powder adheres, and the internal combustion engine performance and denitration performance deteriorate.
以下に、大型低速ディーゼル機関に還元剤としてアンモニア又は尿素水を用いた脱硝触媒部について説明する。外航船に適用される大型低速ディーゼル機関には、２サイクルエンジンが用いられ、２サイクルエンジンの場合には、効率が高いため排気ガス温度は低い。エンジン負荷７５％程度の通常運転時においては、過給機の上流側の排気ガス温度は３５０℃〜４００℃であり、過給機の下流側の排気ガス温度は２５０℃程度である。
図４から図７に脱硝触媒部の配置構成を示す。
なお、図４から図７は説明の便宜上示すものであり、従来実施されていた例とは必ずしも一致しない。
内燃機関１１から排出される排気ガスは、排気レシーバ１２を経由してタービン１３に送られ、その後下流側排気経路３１を通って煙突から排出される。タービン１３とコンプレッサー１４によって過給機１５が構成され、タービン１３の動力によってコンプレッサー１４が駆動され、コンプレッサー１４で圧縮された空気が内燃機関１１に供給される。
Hereinafter, a denitration catalyst unit using ammonia or urea water as a reducing agent in a large-sized low-speed diesel engine will be described. A two-cycle engine is used for a large-sized low-speed diesel engine applied to an ocean-going ship. In the case of a two-cycle engine, the exhaust gas temperature is low because of high efficiency. During normal operation with an engine load of about 75%, the exhaust gas temperature on the upstream side of the supercharger is 350 ° C. to 400 ° C., and the exhaust gas temperature on the downstream side of the supercharger is about 250 ° C.
4 to 7 show the arrangement of the denitration catalyst unit.
4 to 7 are shown for convenience of explanation, and do not necessarily match the example conventionally performed.
Exhaust gas discharged from the internal combustion engine 11 is sent to the turbine 13 via the exhaust receiver 12 and then discharged from the chimney through the downstream exhaust path 31. A turbocharger 15 is configured by the turbine 13 and the compressor 14, the compressor 14 is driven by the power of the turbine 13, and the air compressed by the compressor 14 is supplied to the internal combustion engine 11.
図４に示す第１の脱硝触媒部の配置構成は、排気レシーバ１２とタービン１３との間に、脱硝触媒部２０を配置し、脱硝触媒部２０の上流側排気経路３２から還元剤を供給するものである。
第１の脱硝触媒部の配置構成では、上流側排気経路３２を流れる排気ガス温度は３５０℃〜４００℃であるため、十分な脱硝性能を得ることができる。
しかし、脱硝触媒部２０の熱容量が大きいため、内燃機関１１の動的特性が悪くなる。すなわち、運転開始時や負荷変動時に脱硝触媒部２０の存在によってタービン１３を通過する排気ガスの温度が所定能力を発揮する温度に到達するまでに長時間を要してしまう。このため、脱硝触媒部２０をバイパスする脱硝バイパス経路３３と、この脱硝バイパス経路３３を開閉する脱硝バイパス弁３４を設け、内燃機関１１の運転開始からの所定時間は、脱硝バイパス弁３４を開放して脱硝バイパス経路３３に排気ガスを流すことで対処することが考えられるが、内燃機関１１の特性低下は避けられない。
In the arrangement configuration of the first denitration catalyst section shown in FIG. 4, the denitration catalyst section 20 is disposed between the exhaust receiver 12 and the turbine 13, and the reducing agent is supplied from the upstream exhaust path 32 of the denitration catalyst section 20. Is.
In the arrangement configuration of the first denitration catalyst unit, the exhaust gas temperature flowing through the upstream exhaust passage 32 is 350 ° C. to 400 ° C., so that sufficient denitration performance can be obtained.
However, since the heat capacity of the denitration catalyst unit 20 is large, the dynamic characteristics of the internal combustion engine 11 are deteriorated. That is, it takes a long time for the temperature of the exhaust gas passing through the turbine 13 to reach a temperature at which a predetermined capacity is exhibited due to the presence of the denitration catalyst unit 20 at the start of operation or load fluctuation. Therefore, a denitration bypass path 33 that bypasses the denitration catalyst section 20 and a denitration bypass valve 34 that opens and closes the denitration bypass path 33 are provided, and the denitration bypass valve 34 is opened for a predetermined time from the start of operation of the internal combustion engine 11. Although it is conceivable to deal with exhaust gas flowing through the denitration bypass path 33, deterioration of the characteristics of the internal combustion engine 11 is inevitable.
図５に示す第２の脱硝触媒部の配置構成は、タービン１３を通過した後の排気ガスが流れる下流側排気経路３１に、脱硝触媒部２０を配置し、脱硝触媒部２０の上流に位置する下流側排気経路３１から還元剤を供給するものである。
第２の脱硝触媒部の配置構成では、第１の脱硝触媒部の配置構成のような内燃機関１１の動的特性に影響を与えることはなく、内燃機関１１の特性を低下させない。
しかし、下流側排気経路３１を流れる排気ガス温度は２５０℃程度であるため、尿素の加水分解によるアンモニア生成には十分な温度であるが、２５０℃程度の温度では排気ガス中に含まれるＳＯ２等の硫黄酸化物によって酸性硫安（ＮＨ４ＨＳＯ４）が生成され、触媒表面に白い粉が付着して脱硝性能が低下してしまう。
また、尿素水は２５０℃程度の温度では、分解はするが分散はしにくい。従って、尿素を使わずアンモニアを還元剤として使うことも考えられるが、船舶では毒性の強いアンモニアは保管や管理面で扱いにくい。更に、下流側排気経路３１は大気圧下にある排気ガスを流す配管であるため、上流側排気経路３２と異なり配管径は極めて大きく、従って、大径内を流れる排気ガスに均質に還元剤を分散させることが難しく、還元剤の分散が不十分な場合には脱硝性能を高めることができない。
In the arrangement configuration of the second denitration catalyst unit shown in FIG. 5, the denitration catalyst unit 20 is arranged in the downstream exhaust path 31 through which the exhaust gas after passing through the turbine 13 flows, and is positioned upstream of the denitration catalyst unit 20. A reducing agent is supplied from the downstream exhaust path 31.
In the arrangement configuration of the second denitration catalyst section, the dynamic characteristics of the internal combustion engine 11 as in the arrangement configuration of the first denitration catalyst section are not affected, and the characteristics of the internal combustion engine 11 are not deteriorated.
However, since the temperature of the exhaust gas flowing through the downstream side exhaust passage 31 is about 250 ° C., the temperature is sufficient for ammonia generation by hydrolysis of urea, but at a temperature of about 250 ° C., SO 2 contained in the exhaust gas. Ammonium sulfate (NH 4 HSO 4 ) is generated by sulfur oxides such as, and white powder adheres to the catalyst surface, resulting in a decrease in denitration performance.
Urea water decomposes but is not easily dispersed at a temperature of about 250 ° C. Therefore, it is possible to use ammonia as a reducing agent without using urea, but on ships, ammonia that is highly toxic is difficult to handle in terms of storage and management. Further, since the downstream exhaust passage 31 is a pipe through which exhaust gas under atmospheric pressure flows, the pipe diameter is extremely large unlike the upstream exhaust passage 32. Therefore, the reducing agent is homogeneously applied to the exhaust gas flowing in the large diameter. It is difficult to disperse, and when the reducing agent is not sufficiently dispersed, the denitration performance cannot be improved.
図６に示す第３の脱硝触媒部の配置構成は、タービン１３を通過した後の排気ガスが流れる下流側排気経路３１に脱硝触媒部２０を配置し、上流側排気経路３２からタービン１３をバイパスして脱硝触媒部２０の上流に位置する下流側排気経路３１につながるタービンバイパス経路３５を設けている。そして、タービンバイパス経路３５には、バイパス弁３６を設けてタービンバイパス経路３５を流れる排気ガスを制御する。そして、第３の脱硝触媒部の配置構成は、このタービンバイパス経路３５から還元剤を供給するものである。
第３の脱硝触媒部の配置構成では、第２の脱硝触媒部の配置構成と比較して尿素水の供給を、上流側排気経路３２を流れる高温（３５０℃〜４００℃）の排気ガスに対して行うため、タービンバイパス経路３５では、尿素水の分解能が高いだけでなく分散能も良い。また、酸性硫安の生成量も低く抑えることができる。
しかし、下流側排気経路３１は前述のように上流側排気経路３２と異なり配管径は極めて大きく、従って、タービンバイパス経路３５から下流側排気経路３１への合流箇所では、大径内を流れる排気ガスに均質に還元剤を分散させることが難しく、還元剤の分散が不十分な場合には脱硝性能を高めることができない。
The arrangement of the third denitration catalyst section shown in FIG. 6 is that the denitration catalyst section 20 is disposed in the downstream exhaust path 31 through which the exhaust gas after passing through the turbine 13 flows, and the turbine 13 is bypassed from the upstream exhaust path 32. Thus, a turbine bypass path 35 connected to the downstream exhaust path 31 located upstream of the denitration catalyst unit 20 is provided. The turbine bypass path 35 is provided with a bypass valve 36 to control exhaust gas flowing through the turbine bypass path 35. The arrangement of the third denitration catalyst unit is to supply the reducing agent from the turbine bypass path 35.
In the arrangement configuration of the third denitration catalyst section, compared with the arrangement configuration of the second denitration catalyst section, urea water is supplied to the high-temperature exhaust gas (350 ° C. to 400 ° C.) flowing through the upstream side exhaust passage 32. Therefore, the turbine bypass path 35 has not only high resolution of urea water but also good dispersibility. In addition, the amount of acidic ammonium sulfate produced can be kept low.
However, unlike the upstream exhaust passage 32, the downstream exhaust passage 31 has an extremely large pipe diameter, and therefore, the exhaust gas flowing in the large diameter at the junction from the turbine bypass passage 35 to the downstream exhaust passage 31. It is difficult to uniformly disperse the reducing agent, and when the reducing agent is not sufficiently dispersed, the denitration performance cannot be improved.
図７に示す第４の脱硝触媒部の配置構成は、タービン１３を通過した後の排気ガスが流れる下流側排気経路３１に脱硝触媒部２０を配置し、還元剤としての尿素水を排気レシーバ１２から供給するものである。
第４の脱硝触媒部の配置構成では、第２の脱硝触媒部の配置構成と比較して尿素水の供給を、排気レシーバ１２内の高温（３５０℃〜４００℃）の排気ガスに対して行うため、尿素水の分解能が高いだけでなく分散能も良い。
しかし、尿素水は、壁面等に衝突するとビウレット、シアヌル酸等が重合され固形物が生成されるため、排気レシーバ１２、上流側排気経路３２、及びタービン１３に固形物が付着して、機器性能に悪影響を与えかねない。特にタービン13の翼に固形物が付着した場合には、翼が折損する状況も発生し得る。また、尿素水を導入する排気レシーバ１２では、複数のシリンダーからの排気ガスが吐出弁の開閉動作によって流れ込むために、排気レシーバ１２内は流れが乱れており導入された尿素水が壁に衝突しやすいので排気レシーバ１２内への固形物の付着が非常に多い。
The arrangement of the fourth denitration catalyst unit shown in FIG. 7 is that the denitration catalyst unit 20 is arranged in the downstream exhaust path 31 through which the exhaust gas after passing through the turbine 13 flows, and urea water as a reducing agent is supplied to the exhaust receiver 12. Is supplied from
In the arrangement configuration of the fourth denitration catalyst unit, urea water is supplied to the high-temperature (350 ° C. to 400 ° C.) exhaust gas in the exhaust receiver 12 as compared with the arrangement configuration of the second denitration catalyst unit. Therefore, not only the resolution of urea water is high, but also the dispersibility is good.
However, when urea water collides with a wall surface or the like, since biuret, cyanuric acid, and the like are polymerized and solid matter is generated, the solid matter adheres to the exhaust receiver 12, the upstream exhaust path 32, and the turbine 13, and the equipment performance. May adversely affect In particular, when solid matter adheres to the blades of the turbine 13, a situation in which the blades break may occur. Further, in the exhaust receiver 12 that introduces urea water, exhaust gas from a plurality of cylinders flows in by opening and closing operations of the discharge valves. Therefore, the flow in the exhaust receiver 12 is disturbed, and the introduced urea water collides with the wall. Since it is easy, there is much adhesion of the solid substance in the exhaust receiver 12.
以下に既に提案されている内燃機関の脱硝装置について説明する。
特許文献１は、過給機の上流側の３００℃〜４５０℃の温度域にある排気通路に脱硝装置を設けている。
特許文献２は、排気レシーバ内に脱硝触媒を組み込む構成である。
特許文献３は、過給機の上流側でアンモニアを導入し、過給機の下流側に脱硝装置を設けている。
特許文献４及び特許文献５は、過給機の上流側に脱硝装置を設けるとともに、この脱硝装置をバイパスするバイパス管を設けている。
特許文献６及び特許文献７は、過給機の下流側に脱硝装置を設けるとともに、過給機の上流側の高温ガスの一部を脱硝装置に導くことで脱硝装置内に発生した酸性硫安を分解させるものである。
特許文献８は、過給機の上流側と下流側に脱硝触媒を配置するものである。
特許文献９は、ディーゼルエンジンの排気ガス経路中に脱硝装置を設けたものであり、還元剤として尿素水を用いている。
An already proposed denitration device for an internal combustion engine will be described below.
In Patent Document 1, a denitration device is provided in an exhaust passage in a temperature range of 300 ° C. to 450 ° C. upstream of the supercharger.
Patent document 2 is a structure which incorporates a denitration catalyst in an exhaust receiver.
In Patent Document 3, ammonia is introduced on the upstream side of the supercharger, and a denitration device is provided on the downstream side of the supercharger.
In Patent Documents 4 and 5, a denitration device is provided on the upstream side of the supercharger, and a bypass pipe that bypasses the denitration device is provided.
In Patent Document 6 and Patent Document 7, a denitration device is provided on the downstream side of the supercharger, and part of the high-temperature gas upstream of the supercharger is guided to the denitration device, so that acidic ammonium sulfate generated in the denitration device is reduced. It is to be decomposed.
Patent document 8 arrange | positions a denitration catalyst in the upstream and downstream of a supercharger.
In Patent Document 9, a denitration device is provided in an exhaust gas path of a diesel engine, and urea water is used as a reducing agent.
特許文献１は、第１の脱硝触媒部の配置構成で説明したように、内燃機関の特性が低下してしまう。
特許文献２は、アンモニアを還元剤として用いており、アンモニアの強い毒性のために、船舶用として用いることは難しい。なお、特許文献２の構成で、アンモニアに代えて尿素水を用いたとすると、第４の脱硝触媒部の配置構成で説明したように、排気レシーバ内に固形物が付着するという問題が生じる。
特許文献３についても、アンモニアを還元剤として用いており、アンモニアの強い毒性のために、船舶用として用いることは難しい。なお、特許文献３の構成で、アンモニアに代えて尿素水を用いたとすると、第４の脱硝触媒部の配置構成で説明したように、特にタービン内に固形物が付着するという問題が生じる。
特許文献４及び特許文献５は、第１の脱硝触媒部の配置構成で説明したように、内燃機関の特性の低下は避けられない。
特許文献６及び特許文献７は、発生する酸性硫安の分解機能を備えているが、第２の脱硝触媒部の配置構成で説明したように、過給機の下流側配管は、上流側配管と異なり配管径が極めて大きいために、大径内を流れる排気ガスに均質に還元剤を分散させることが難しく、還元剤の分散が不十分な場合には脱硝性能を高めることができない。
特許文献８は、還元触媒として各種ゼオライト系触媒、アルミナ系触媒を用いたものであり、還元剤も炭化水素若しくはアルコールを用いたものであり、アンモニアや尿素水を用いたものではない。
なお、特許文献９は、アンモニアは毒性が強い上に取り扱いが難しいという問題点を指摘している。
In Patent Document 1, as described in the arrangement configuration of the first denitration catalyst unit, the characteristics of the internal combustion engine are deteriorated.
Patent Document 2 uses ammonia as a reducing agent, and is difficult to use for ships because of the strong toxicity of ammonia. In addition, if urea water is used instead of ammonia in the configuration of Patent Document 2, as described in the arrangement configuration of the fourth denitration catalyst unit, there arises a problem that solids adhere to the exhaust receiver.
Patent Document 3 also uses ammonia as a reducing agent and is difficult to use for ships because of the strong toxicity of ammonia. Note that if urea water is used instead of ammonia in the configuration of Patent Document 3, there is a problem that solid matter particularly adheres to the turbine as described in the arrangement configuration of the fourth denitration catalyst unit.
In Patent Documents 4 and 5, as described in the arrangement configuration of the first denitration catalyst unit, the deterioration of the characteristics of the internal combustion engine is inevitable.
Patent Document 6 and Patent Document 7 have a function of decomposing the generated acidic ammonium sulfate. As described in the arrangement configuration of the second denitration catalyst unit, the downstream pipe of the supercharger is connected to the upstream pipe. In contrast, since the pipe diameter is extremely large, it is difficult to uniformly disperse the reducing agent in the exhaust gas flowing in the large diameter, and if the reducing agent is not sufficiently dispersed, the denitration performance cannot be improved.
Patent Document 8 uses various zeolite-based catalysts and alumina-based catalysts as reduction catalysts, and the reducing agent also uses hydrocarbons or alcohols, and does not use ammonia or urea water.
Patent Document 9 points out that ammonia is highly toxic and difficult to handle.
そこで本発明は、尿素水を用いた場合の固形物の付着の問題を無くすとともに、内燃機関の特性を維持でき、大径内を流れる排気ガスに均質に還元剤を分散させることができる内燃機関用脱硝装置及びこの内燃機関用脱硝装置を搭載する船舶を提供することを目的とする。 Therefore, the present invention eliminates the problem of solid matter adhesion when urea water is used, maintains the characteristics of the internal combustion engine, and can uniformly disperse the reducing agent in the exhaust gas flowing in the large diameter. An object of the present invention is to provide a denitration apparatus for a vehicle and a ship equipped with the denitration apparatus for an internal combustion engine.
請求項１記載に対応した内燃機関用脱硝装置においては、内燃機関と、内燃機関の排気経路に設けた過給機と、過給機の下流側の下流側排気経路に設けた下流側脱硝触媒部と、過給機の上流側の上流側排気経路に設けた下流側脱硝触媒部よりも小型の上流側脱硝触媒部と、上流側脱硝触媒部の更に上流側の上流側排気経路の内部に尿素水を供給する尿素水供給手段と、上流側脱硝触媒部の更に上流側の上流側排気経路の分岐点から分岐し、上流側脱硝触媒部の下流側で過給機の上流側排気経路に合流する脱硝バイパス経路と、上流側排気経路と脱硝バイパス経路を切り換えるために開閉する分岐点以降に設けた開閉手段とを備え、上流側排気経路に設けた温度センサで検出される内燃機関の排気ガス温度が設定温度を超えない内燃機関の運転開始時又は極低速運転時に、開閉手段により上流側排気経路を閉じて脱硝バイパス経路を開き尿素水供給手段の動作を止め、排気ガス温度が設定温度を超えた定常運転時に、開閉手段により上流側排気経路を開き脱硝バイパス経路を閉じて尿素水供給手段を動作させたことを特徴とする。請求項１に記載の本発明によれば、還元剤として尿素水を用いることで、例えば船舶のような場所でも安全に取り扱うことができる。また、本発明によれば、過給機の上流側の高温排気ガス中に尿素水を供給することで、尿素水を十分に分解し分散させることができる。また、本発明によれば、過給機の上流側に小型の上流側脱硝触媒部を設けることで、熱容量の増加による内燃機関の特性の低下を防止でき、また尿素水の供給による固形物の付着を防止することができる。また、本発明によれば、過給機の下流側に大型の下流側脱硝触媒部を設けることで、内燃機関の特性に影響を与えることなく、脱硝能力を高めることができる。また、本発明によれば、内燃機関の運転開始時や負荷変動時に脱硝バイパス経路に排気ガスを流すことで内燃機関の動的特性の低下を更に抑制することができる。また、本発明によれば、内燃機関の運転開始時や極低速運転時に開閉手段によって脱硝バイパス経路を開くことで内燃機関の効率低下を防止することができる。
なお、下流側脱硝触媒部及び上流側脱硝触媒部には、脱硝触媒として、窒素酸化物を還元する反応を速めることに寄与するもの、尿素をアンモニアに分解する反応を速めることに寄与するものを単独あるいは組み合わせて、また、一つの触媒で双方の機能を有したもの等を適宜使用することができる。
請求項２記載の本発明は、請求項１に記載の内燃機関用脱硝装置において、下流側脱硝触媒部及び／又は上流側脱硝触媒部の温度を上げる昇温手段を更に備えたことを特徴とする。請求項２に記載の本発明によれば、排気ガス温度を上昇させることができ、尿素水の分解能や分散能を高め、排気ガス中に硫黄酸化物が含まれている場合に酸性硫安の発生を抑え、又は発生した酸性硫安を分解することができる。
請求項３記載の本発明は、請求項２に記載の内燃機関用脱硝装置において、昇温手段は、過給機の上流側排気経路から排気ガスを取り出す排気ガス抽気手段及び／又は内燃機関へ過給機から給気を行う給気経路から空気を取り出す空気抽気手段であることを特徴とする。請求項３に記載の本発明によれば、上流側排気経路から排気ガスを取り出し、及び／又は給気経路から空気を取り出すことで、過給効率が低下し、排気ガス温度を上昇させることができ、尿素水の分解能や分散能を高め、酸性硫安の発生を抑え、又は発生した酸性硫安を分解することができる。
請求項４記載の本発明は、請求項１から請求項３に記載の内燃機関用脱硝装置において、下流側脱硝触媒部の触媒及び／又は上流側脱硝触媒部の触媒を再生する再生用加熱手段を更に備えたことを特徴とする。請求項４に記載の本発明によれば、触媒を加熱することで、触媒に付着した酸性硫安を除去することができる。
請求項５記載の本発明は、請求項４に記載の内燃機関用脱硝装置において、下流側脱硝酸触媒部の触媒として低温用脱硝触媒を、また上流側脱硝触媒部の触媒として高温用脱硝触媒を用いたことを特徴とする。請求項５に記載の本発明によれば、下流側脱硝触媒部には低温の排気ガスが流れ、上流側脱硝触媒部には高温の排気ガスが流れるため、それぞれの排気ガスの温度に応じた脱硝を効率よく行うことができる。
請求項６記載の本発明は、請求項１から請求項５に記載の内燃機関用脱硝装置において、内燃機関が、大型で低速のディーゼル機関であることを特徴とする。請求項６に記載の本発明によれば、大型で低速のディーゼル機関では機関効率が高く排気ガス温度が十分に高くないために、過給機の上流側の高温排気ガス中に尿素水を供給することで、還元剤を十分に分解し分散させることができ、過給機の上流側には小型の上流側脱硝触媒部を設けることで、熱容量の増加による内燃機関の特性の低下を防止でき、また尿素水の供給による固形物の付着を防止することができ、過給機の下流側に大型の下流側脱硝触媒部を設けることで、内燃機関の特性に影響を与えることなく、脱硝能力を高めることができる。
請求項７記載に対応した船舶においては、請求項１から請求項６のいずれかに記載の内燃機関用脱硝装置を搭載したことを特徴とする。請求項７に記載の本発明によれば、毒性が高く取り扱いが困難なアンモニアではなく、尿素水を還元剤として用いるために、船舶でも安全に取り扱うことができる。
In an internal combustion engine denitration apparatus corresponding to claim 1, wherein the internal combustion engine and a turbocharger provided in an exhaust passage of an internal combustion engine, downstream denitration catalyst disposed on the downstream side exhaust passage on the downstream side of the turbocharger And an upstream side denitration catalyst part that is smaller than the downstream side denitration catalyst part provided in the upstream side exhaust path of the turbocharger, and an upstream side exhaust path that is further upstream of the upstream side denitration catalyst part. a urea water supply means for supplying urea water branched from the branch point of the further upstream side of the upstream-side exhaust passage of the upper stream side denitration catalyst unit, the upper stream side of the supercharger at the downstream side of the upper stream side denitration catalyst unit An internal combustion engine that includes a denitration bypass path that joins the exhaust path, and an opening / closing means that is provided after the branch point that opens and closes to switch between the upstream exhaust path and the denitration bypass path, and that is detected by a temperature sensor provided in the upstream exhaust path operation of the internal combustion engine in which the exhaust gas temperature of the engine does not exceed the set temperature Hajimeji or during very low speed operation, the denitration bypass path by closing the upstream-side exhaust path stopping the operation of the open-out the urea water supply unit, at the time of steady operation the exhaust gas temperature exceeds the set temperature by opening and closing means, upstream the closing means The urea water supply means is operated by opening the side exhaust path and closing the denitration bypass path . According to the first aspect of the present invention, by using urea water as the reducing agent, it can be safely handled even in places such as ships. Further, according to the present invention, the urea water can be sufficiently decomposed and dispersed by supplying the urea water into the high-temperature exhaust gas upstream of the supercharger. In addition, according to the present invention, by providing a small upstream denitration catalyst section upstream of the supercharger, it is possible to prevent deterioration of the characteristics of the internal combustion engine due to an increase in heat capacity. Adhesion can be prevented. Further, according to the present invention, by providing a large downstream denitration catalyst section downstream of the supercharger, it is possible to increase the denitration capability without affecting the characteristics of the internal combustion engine. Further, according to the present invention, it is possible to further suppress the deterioration of the dynamic characteristics of the internal combustion engine by causing the exhaust gas to flow through the denitration bypass path at the start of operation of the internal combustion engine or when the load changes. Further, according to the present invention, the efficiency reduction of the internal combustion engine can be prevented by opening the denitration bypass path by the opening / closing means at the start of operation of the internal combustion engine or at an extremely low speed operation.
In addition, the downstream denitration catalyst part and the upstream denitration catalyst part include a denitration catalyst that contributes to speeding up the reaction of reducing nitrogen oxides and that contributes to speeding up the reaction of decomposing urea into ammonia. A single catalyst having both functions or the like can be appropriately used alone or in combination.
The present invention described in claim 2 is the denitration apparatus for an internal combustion engine according to claim 1, further comprising a temperature raising means for raising the temperature of the downstream denitration catalyst part and / or the upstream denitration catalyst part. To do. According to the second aspect of the present invention, the temperature of the exhaust gas can be raised, the resolution and dispersibility of urea water are improved, and the generation of acidic ammonium sulfate when sulfur oxide is contained in the exhaust gas. Or the generated acidic ammonium sulfate can be decomposed.
According to a third aspect of the present invention, in the denitration apparatus for an internal combustion engine according to the second aspect, the temperature raising means is an exhaust gas extraction means for extracting exhaust gas from the upstream exhaust path of the supercharger and / or the internal combustion engine. It is an air extraction means for extracting air from an air supply path for supplying air from a supercharger. According to the third aspect of the present invention, it is possible to reduce the supercharging efficiency and raise the exhaust gas temperature by taking out the exhaust gas from the upstream exhaust passage and / or taking out the air from the air supply passage. It is possible to improve the resolution and dispersibility of urea water, suppress the generation of acidic ammonium sulfate, or decompose the generated acidic ammonium sulfate.
According to a fourth aspect of the present invention, in the denitration apparatus for an internal combustion engine according to the first to third aspects, a regeneration heating means for regenerating the catalyst in the downstream denitration catalyst section and / or the catalyst in the upstream denitration catalyst section. Is further provided. According to this invention of Claim 4, the acidic ammonium sulfate adhering to a catalyst can be removed by heating a catalyst.
According to a fifth aspect of the invention, in the internal combustion engine for a denitration apparatus according to 請 Motomeko 4, high temperature denitration a low-temperature denitration catalyst as the catalyst of the downstream de nitrate catalyst unit, also as the upstream denitration catalyst of the catalyst It is characterized by using a catalyst. According to the fifth aspect of the present invention, the low-temperature exhaust gas flows through the downstream side denitration catalyst unit, and the high-temperature exhaust gas flows through the upstream side denitration catalyst unit, so that it corresponds to the temperature of each exhaust gas. Denitration can be performed efficiently.
According to a sixth aspect of the present invention, in the denitration device for an internal combustion engine according to the first to fifth aspects, the internal combustion engine is a large-sized and low-speed diesel engine. According to the sixth aspect of the present invention, since a large and low-speed diesel engine has high engine efficiency and the exhaust gas temperature is not sufficiently high, urea water is supplied into the high-temperature exhaust gas upstream of the supercharger. Thus, the reducing agent can be sufficiently decomposed and dispersed, and by providing a small upstream denitration catalyst section upstream of the supercharger, it is possible to prevent deterioration of the internal combustion engine characteristics due to an increase in heat capacity. In addition, it is possible to prevent the adhesion of solid matter due to the supply of urea water, and by providing a large downstream denitration catalyst section downstream of the turbocharger, the denitration capacity is not affected without affecting the characteristics of the internal combustion engine. Can be increased.
A ship corresponding to claim 7 is equipped with the denitration device for an internal combustion engine according to any one of claims 1 to 6. According to the seventh aspect of the present invention, since urea water is used as a reducing agent instead of ammonia which is highly toxic and difficult to handle, it can be handled safely on ships.
本発明の内燃機関用脱硝装置によれば、還元剤として尿素水を用いることで、安全に取り扱うことができ、過給機の上流側の高温排気ガス中に尿素水を供給することで、尿素水を十分に分解し分散させることができ、過給機の上流側に小型の上流側脱硝触媒部を設けることで、熱容量の増加による内燃機関の特性の低下を防止でき、また尿素水の供給による固形物の付着を防止することができ、過給機の下流側に大型の下流側脱硝触媒部を設けることで、内燃機関の特性に影響を与えることなく、脱硝能力を高めることができる。
なお、下流側脱硝触媒部及び／又は上流側脱硝触媒部の温度を上げる昇温手段を更に備えた場合には、排気ガス温度を上昇させることができ、尿素水の分解能や分散能を高め、酸性硫安の発生を抑え、又は発生した酸性硫安を分解することができる。
また、昇温手段が、過給機の上流側排気経路から排気ガスを取り出す排気ガス抽気手段及び／又は内燃機関へ過給機から給気を行う給気経路から空気を取り出す空気抽気手段である場合には、排気経路から排気ガスを取り出し、及び／又は給気経路から空気を取り出すことで、過給効率が低下し、排気ガス温度を上昇させることができ、尿素水の分解能や分散能を高め、酸性硫安の発生を抑え、又は発生した酸性硫安を分解することができる。
また、下流側脱硝触媒部の触媒及び／又は上流側脱硝触媒部の触媒を再生する再生用加熱手段を更に備えた場合には、触媒を直接あるいは間接的に加熱することで、触媒に付着した酸性硫安を除去することができる。
また、上流側脱硝触媒部の上流側排気経路から分岐し、上流側脱硝触媒部の下流側で過給機の上流側排気経路に合流する脱硝バイパス経路を更に備えた場合には、内燃機関の運転開始時や負荷変動時に脱硝バイパス経路に排気ガスを流すことで内燃機関の動的特性の低下を更に抑制することができる。
また、脱硝バイパス経路を開閉する開閉手段を更に備えた場合には、内燃機関の運転開始時や極低速運転時に開閉手段によって脱硝バイパス経路を開き、定常運転時には閉じることで内燃機関の効率低下を防止し、定常運転時には脱硝を正常に行うことができる。
また、下流側脱硝酸触媒部の触媒として低温用脱硝触媒を、また上流側脱硝触媒部の触媒として高温用脱硝触媒を用いた場合には、下流側脱硝触媒部には低温の排気ガスが流れ、上流側脱硝触媒部には高温の排気ガスが流れるため、それぞれの排気ガスの温度に応じた脱硝を効率よく行うことができる。
また、内燃機関が、大型で低速のディーゼル機関である場合には、機関内の排気ガス温度が十分に高くはないが、過給機の上流側の高温排気ガス中に尿素水を供給することで、還元剤を十分に分解し分散させることができ、過給機の上流側には小型の上流側脱硝触媒部を設けることで、熱容量の増加による内燃機関の特性の低下を防止でき、また尿素水の供給による固形物の付着を防止することができ、過給機の下流側に大型の下流側脱硝触媒部を設けることで、内燃機関の特性に影響を与えることなく、脱硝能力を高めることができる。
本発明の船舶によれば、毒性が高く取り扱いが困難なアンモニアではなく、尿素水を還元剤として用いるために、船舶上で安全に取り扱うことができる。
According to the denitration device for an internal combustion engine of the present invention, urea water can be used safely as a reducing agent, and urea water can be handled by supplying urea water into the high-temperature exhaust gas upstream of the supercharger. Water can be sufficiently decomposed and dispersed, and by providing a small upstream denitration catalyst section upstream of the turbocharger, it is possible to prevent deterioration of the characteristics of the internal combustion engine due to an increase in heat capacity, and supply of urea water It is possible to prevent the solid matter from adhering, and by providing a large downstream denitration catalyst section downstream of the supercharger, it is possible to enhance the denitration capability without affecting the characteristics of the internal combustion engine.
In addition, in the case of further comprising a temperature raising means for raising the temperature of the downstream side denitration catalyst part and / or the upstream side denitration catalyst part, the exhaust gas temperature can be raised, and the resolution and dispersibility of urea water are improved, The generation of acidic ammonium sulfate can be suppressed or the generated acidic ammonium sulfate can be decomposed.
The temperature raising means is an exhaust gas extraction means for extracting exhaust gas from the upstream exhaust path of the supercharger and / or an air extraction means for extracting air from an air supply path for supplying air from the supercharger to the internal combustion engine. In this case, by taking out the exhaust gas from the exhaust path and / or taking out the air from the air supply path, the supercharging efficiency can be lowered and the exhaust gas temperature can be raised, and the resolution and dispersibility of urea water can be improved. The generation of acidic ammonium sulfate can be suppressed, or the generated acidic ammonium sulfate can be decomposed.
In addition, when further equipped with a heating means for regeneration that regenerates the catalyst in the downstream denitration catalyst section and / or the catalyst in the upstream denitration catalyst section, the catalyst is attached to the catalyst by directly or indirectly heating the catalyst. Acidic ammonium sulfate can be removed.
Further, in the case of further comprising a denitration bypass path that branches from the upstream exhaust path of the upstream denitration catalyst section and merges with the upstream exhaust path of the turbocharger on the downstream side of the upstream denitration catalyst section, By flowing the exhaust gas through the denitration bypass path at the start of operation or when the load fluctuates, it is possible to further suppress the deterioration of dynamic characteristics of the internal combustion engine.
In addition, when an opening / closing means for opening / closing the denitration bypass path is further provided, the efficiency of the internal combustion engine is reduced by opening the denitration bypass path by the opening / closing means at the start of operation of the internal combustion engine or at an extremely low speed operation, and closing at the normal operation. It is possible to prevent denitration during normal operation.
In addition, when a low-temperature denitration catalyst is used as the catalyst for the downstream denitration catalyst section and a high-temperature denitration catalyst is used as the catalyst for the upstream denitration catalyst section, the low-temperature exhaust gas flows through the downstream denitration catalyst section. Since the high-temperature exhaust gas flows through the upstream denitration catalyst section, denitration according to the temperature of each exhaust gas can be performed efficiently.
If the internal combustion engine is a large and low speed diesel engine, the exhaust gas temperature in the engine is not sufficiently high, but urea water is supplied into the high temperature exhaust gas upstream of the turbocharger. Thus, the reducing agent can be sufficiently decomposed and dispersed, and by providing a small upstream denitration catalyst section upstream of the supercharger, it is possible to prevent deterioration of the characteristics of the internal combustion engine due to an increase in heat capacity, and Solid matter adhesion due to urea water supply can be prevented, and by providing a large downstream denitration catalyst section downstream of the turbocharger, the denitration capability is increased without affecting the characteristics of the internal combustion engine. be able to.
According to the ship of the present invention, urea water is used as a reducing agent instead of ammonia, which is highly toxic and difficult to handle, and can be handled safely on the ship.
以下に、本発明の実施形態による内燃機関用脱硝装置について説明する。
図１は本実施形態による内燃機関用脱硝装置の構成図である。
本実施形態による内燃機関用脱硝装置は、内燃機関１１と、内燃機関１１の排気経路に設けた過給機１５と、過給機１５の下流側排気経路３１に設けた下流側脱硝触媒部２１と、過給機１５の上流側排気経路３２に設けた上流側脱硝触媒部２２と、上流側脱硝触媒部２２よりも上流側に位置する上流側排気経路３２の内部に尿素水を供給する尿素水供給手段１６とを備えている。
本実施形態では、内燃機関１１を外航船に適用される大型低速ディーゼル機関として説明する。この種の大型低速ディーゼル機関には２サイクルエンジンが用いられ、機械回転数が約７０ｒｐｍ〜１５０ｒｐｍ程度のものである。
Hereinafter, a denitration apparatus for an internal combustion engine according to an embodiment of the present invention will be described.
FIG. 1 is a configuration diagram of a denitration device for an internal combustion engine according to the present embodiment.
The internal combustion engine denitration apparatus according to the present embodiment includes an internal combustion engine 11, a supercharger 15 provided in the exhaust path of the internal combustion engine 11, and a downstream denitration catalyst unit 21 provided in a downstream exhaust path 31 of the supercharger 15. And an upstream denitration catalyst part 22 provided in the upstream exhaust path 32 of the supercharger 15 and urea for supplying urea water into the upstream exhaust path 32 located upstream from the upstream denitration catalyst part 22 Water supply means 16.
In the present embodiment, the internal combustion engine 11 will be described as a large-sized low-speed diesel engine applied to an ocean-going ship. A two-cycle engine is used for this type of large-sized low-speed diesel engine, and the machine rotation speed is about 70 rpm to about 150 rpm.
下流側脱硝触媒部２１及び上流側脱硝触媒部２２は、排気ガス中に含まれる窒素酸化物（ＮＯｘ）をアンモニアと反応させて分解するための触媒部を備えている。触媒部には、チタン・バナジウム系の金属が用いられる。例えば、バナジウム（Ｖ）、モリブテン（Ｍｏ）、又はタングステン（Ｗ）を活性成分とした酸化チタン（ＴｉＯ２）系触媒が使用される。触媒部は排気ガス通路内に配置され、排気ガスとの接触面積を広くするために平板や触媒の細管を束ねた構造としており、例えばハニカム構造が適している。
下流側脱硝触媒部２１は、大型の触媒部として構成され、脱硝触媒の空間速度（ＳＶ）を５０００ｈ−１とし、上流側脱硝触媒部２２は、小型の触媒部として構成され、脱硝触媒の空間速度（ＳＶ）を５００００ｈ−１とする。このように、下流側脱硝触媒部２１と上流側脱硝触媒部２２との空間速度比を１対１０程度にして、上流側脱硝触媒部２２を下流側脱硝触媒部２１よりも１０分の１程度の大きさに小型とする。
また、下流側脱硝酸触媒部２１の触媒として低温用脱硝触媒を、また上流側脱硝触媒部２２の触媒として高温用脱硝触媒を用いる。ここで、低温用脱硝触媒の反応温度は２５０℃程度、高温用脱硝触媒の反応温度は３５０℃〜４００℃とする。例えば活性成分であるバナジウムの含有量を多くすることで低温用脱硝触媒とし、バナジウムの含有量を少なくすることで高温用脱硝触媒とすることができる。
The downstream denitration catalyst unit 21 and the upstream denitration catalyst unit 22 include a catalyst unit for reacting nitrogen oxide (NOx) contained in the exhaust gas with ammonia and decomposing it. A titanium / vanadium metal is used for the catalyst portion. For example, a titanium oxide (TiO 2 ) -based catalyst containing vanadium (V), molybdenum (Mo), or tungsten (W) as an active component is used. The catalyst portion is disposed in the exhaust gas passage and has a structure in which flat plates and catalyst thin tubes are bundled in order to increase the contact area with the exhaust gas. For example, a honeycomb structure is suitable.
The downstream denitration catalyst unit 21 is configured as a large catalyst unit, and the space velocity (SV) of the denitration catalyst is set to 5000 h −1 , and the upstream denitration catalyst unit 22 is configured as a small catalyst unit, and the space of the denitration catalyst The speed (SV) is set to 50000h- 1 . Thus, the space velocity ratio between the downstream side denitration catalyst unit 21 and the upstream side denitration catalyst unit 22 is set to about 1:10, and the upstream side denitration catalyst unit 22 is about 1/10 of the downstream side denitration catalyst unit 21. The size is small.
Further, a low-temperature denitration catalyst is used as the catalyst of the downstream denitration catalyst unit 21, and a high-temperature denitration catalyst is used as the catalyst of the upstream denitration catalyst unit 22. Here, the reaction temperature of the low-temperature denitration catalyst is about 250 ° C., and the reaction temperature of the high-temperature denitration catalyst is 350 ° C. to 400 ° C. For example, a denitration catalyst for low temperature can be obtained by increasing the content of vanadium as an active ingredient, and a denitration catalyst for high temperature by reducing the content of vanadium.
尿素水供給手段１６は、図示しないが、尿素水（（ＮＨ２）２ＣＯ＋Ｈ２Ｏ）を蓄えるタンクや、上流側排気経路３２の内部に尿素水を噴出する噴射ノズル、噴出に必要な加圧のためのポンプやコンプレッサーを備えて構成されている。
過給機１５は、タービン１３とコンプレッサー１４によって構成され、排気ガスによってタービン１３を駆動し、タービン１３の動力によってコンプレッサー１４が駆動され、コンプレッサー１４で圧縮された空気が内燃機関１１に供給される。
Although not shown, the urea water supply means 16 is a tank that stores urea water ((NH 2 ) 2 CO + H 2 O), an injection nozzle that jets urea water into the upstream side exhaust passage 32, and a pressurization necessary for jetting. It is configured with a pump and compressor for.
The supercharger 15 includes a turbine 13 and a compressor 14. The turbine 13 is driven by exhaust gas, the compressor 14 is driven by the power of the turbine 13, and air compressed by the compressor 14 is supplied to the internal combustion engine 11. .
内燃機関１１の複数の気筒から排出される排気ガスは、排気レシーバ１２を経由してタービン１３に送られ、その後下流側排気経路３１を通って煙突から排出される。
エンジン負荷７５％程度の通常運転時においては、過給機１５の上流側排気経路３２を流れる排気ガス温度は３５０℃〜４００℃であり、過給機１５の下流側排気経路３１を流れる排気ガス温度は２５０℃程度である。
尿素水供給手段１６は、３５０℃〜４００℃の温度域にある上流側排気経路３２に尿素水を供給するため、加水分解によってアンモニアが生成されるとともに上流側排気経路３２内で十分に分散する。また、通常運転時においては、３５０℃以上の温度であるため、排気ガス中にＳＯ２等の硫黄酸化物が存在するが、酸性硫安（ＮＨ４ＨＳＯ４）は生成されにくい。
そして、尿素水供給手段１６の下流側には、上流側脱硝触媒部２２が設けられているため、上流側脱硝触媒部２２では、分散したアンモニアによって脱硝が促進される。また、尿素水供給手段１６の下流側に上流側脱硝触媒部２２が設けられているため、排気ガス温度が低下した場合などで、尿素水が残留し、固形物が生成され、あるいは酸性硫安が生成された場合には、上流側脱硝触媒部２２で捕集されるため、下流側のタービン１３への弊害を防ぐことができる。
上流側脱硝触媒部２２は、小型としているため、未反応のアンモニアは分散した状態で下流側排気経路３１に導かれるが、タービン13によって更に撹拌されて供給されるため、大径内を流れる排気ガスに均質にアンモニアを分散させることができ、下流側脱硝触媒部２１で脱硝が行われる。
Exhaust gas discharged from the plurality of cylinders of the internal combustion engine 11 is sent to the turbine 13 via the exhaust receiver 12 and then discharged from the chimney through the downstream exhaust path 31.
During normal operation with an engine load of about 75%, the temperature of the exhaust gas flowing through the upstream exhaust path 32 of the supercharger 15 is 350 ° C. to 400 ° C., and the exhaust gas flowing through the downstream exhaust path 31 of the supercharger 15 The temperature is about 250 ° C.
Since the urea water supply means 16 supplies urea water to the upstream exhaust passage 32 in the temperature range of 350 ° C. to 400 ° C., ammonia is generated by hydrolysis and is sufficiently dispersed in the upstream exhaust passage 32. . Further, during normal operation, since the temperature is 350 ° C. or higher, sulfur oxides such as SO 2 are present in the exhaust gas, but acidic ammonium sulfate (NH 4 HSO 4 ) is hardly generated.
And since the upstream denitration catalyst part 22 is provided in the downstream of the urea water supply means 16, in the upstream denitration catalyst part 22, denitration is promoted by the dispersed ammonia. Further, since the upstream denitration catalyst unit 22 is provided downstream of the urea water supply means 16, when the exhaust gas temperature is lowered, urea water remains, solids are generated, or acidic ammonium sulfate is not generated. When generated, it is collected by the upstream-side denitration catalyst unit 22, so that adverse effects on the downstream turbine 13 can be prevented.
Since the upstream denitration catalyst unit 22 is small in size, unreacted ammonia is led to the downstream exhaust passage 31 in a dispersed state, but is further stirred and supplied by the turbine 13, so that the exhaust flowing in the large diameter Ammonia can be uniformly dispersed in the gas, and denitration is performed in the downstream denitration catalyst section 21.
以上のように本実施形態によれば、還元剤として尿素水を用いることで、船舶でも安全に取り扱うことができる。
また、本実施形態によれば、過給機１５の上流側の高温排気ガス中に尿素水を供給することで、尿素水を十分に分解し分散させることができる。
また、本実施形態によれば、過給機１５の上流側に小型の上流側脱硝触媒部２２を設けることで、熱容量の増加による内燃機関１１の特性の低下を防止でき、また尿素水の供給による固形物の付着を防止することができる。
また、本実施形態によれば、過給機１５の下流側に大型の下流側脱硝触媒部２１を設けることで、内燃機関１１の特性に影響を与えることなく、脱硝能力を高めることができる。
As described above, according to the present embodiment, by using urea water as a reducing agent, it can be handled safely on a ship.
Further, according to this embodiment, the urea water can be sufficiently decomposed and dispersed by supplying the urea water into the high-temperature exhaust gas upstream of the supercharger 15.
In addition, according to the present embodiment, by providing the small upstream denitration catalyst unit 22 upstream of the supercharger 15, it is possible to prevent deterioration of the characteristics of the internal combustion engine 11 due to an increase in heat capacity, and supply of urea water It is possible to prevent the solid matter from adhering.
Further, according to the present embodiment, by providing the large downstream denitration catalyst portion 21 on the downstream side of the supercharger 15, it is possible to increase the denitration capability without affecting the characteristics of the internal combustion engine 11.
また本実施形態による内燃機関用脱硝装置は、過給機１５の上流側排気経路３２から排気ガスを取り出す排気ガス抽気手段４３と、内燃機関１１へ過給機１５から給気を行う給気経路１７から空気を取り出す空気抽気手段４４を備えている。なお、図１では、排気ガス抽気手段４３は、上流側排気経路３２の一部を構成する排気レシーバ１２から排気ガスを取り出す場合を示しているが、上流側排気経路３２の任意の箇所から取り出すことができる。排気ガス抽気手段４３及び／又は空気抽気手段４４は、昇温手段として用いる。
ここで、上流側排気経路３２からの排気ガスの取り出しによる排気ガスの温度上昇、又は給気経路１７からの空気の取り出しによる排気ガスの温度上昇は、排気ガス又は給気空気の１０％を取り出すことで約５０℃上昇することが実験によって明らかとなっている。
本実施形態によれば、上流側排気経路３２から排気ガスを取り出し、又は給気経路１７から空気を取り出すことで、過給機１５での過給効率が低下し、排気ガス温度を上昇させることができ、尿素水の分解能や分散能を高め、酸性硫安の発生を抑え、又は発生した酸性硫安を分解することができる。
なお、昇温手段には、排気ガス抽気手段４３や空気抽気手段４４ではなく、電熱式ヒータや加熱バーナーを用いてもよい。図１では、下流側脱硝触媒部２１の上流側に位置する下流側排気経路３１に加熱バーナー４５を設けている。
Further, the internal combustion engine denitration apparatus according to the present embodiment includes an exhaust gas extraction means 43 that extracts exhaust gas from the upstream exhaust path 32 of the supercharger 15, and an air supply path that supplies air to the internal combustion engine 11 from the supercharger 15. An air bleeder 44 for taking out air from 17 is provided. In FIG. 1, the exhaust gas extraction means 43 shows a case where the exhaust gas is taken out from the exhaust receiver 12 that constitutes a part of the upstream exhaust path 32, but is taken out from an arbitrary part of the upstream exhaust path 32. be able to. The exhaust gas extraction means 43 and / or the air extraction means 44 are used as a temperature raising means.
Here, the temperature rise of the exhaust gas due to the extraction of the exhaust gas from the upstream side exhaust passage 32 or the temperature rise of the exhaust gas due to the removal of air from the supply passage 17 takes out 10% of the exhaust gas or the supply air. It is clear from experiments that the temperature rises by about 50 ° C.
According to the present embodiment, by taking out the exhaust gas from the upstream exhaust passage 32 or taking out the air from the air supply passage 17, the supercharging efficiency in the supercharger 15 is lowered and the exhaust gas temperature is raised. It is possible to improve the resolution and dispersibility of urea water, suppress the generation of acidic ammonium sulfate, or decompose the generated acidic ammonium sulfate.
In addition, instead of the exhaust gas extraction means 43 and the air extraction means 44, an electric heater or a heating burner may be used as the temperature raising means. In FIG. 1, a heating burner 45 is provided in the downstream exhaust passage 31 located on the upstream side of the downstream denitration catalyst unit 21.
また本実施形態による内燃機関用脱硝装置は、下流側脱硝触媒部２１の触媒と上流側脱硝触媒部２２の触媒を再生する再生用加熱手段４１、４２を備えている。再生用加熱手段４１、４２には、例えば加熱ヒータや加熱バーナーを用いることができ、脱硝触媒を直接加熱する。
本実施形態によれば、下流側脱硝触媒部２１及び上流側脱硝触媒部２２に付着する酸性硫安や固形物の付着を再生用加熱手段４１、４２によって分解し、気化させることができる。
なお、下流側脱硝触媒部２１だけに再生用加熱手段４１を設けてもよく、逆に上流側脱硝触媒部２２だけに再生用加熱手段４２を設けてもよい。
また、これら加熱バーナー45や再生用加熱手段４１、４２は、内燃機関11の運転中に作動させ、触媒の温度を直接的あるいは間接的に高温に保ち酸性硫安や固形物の触媒への付着を抑制したり、内燃機関11の運転停止後の再生運転時に作動させ、触媒に付着した酸性硫安や固形物を昇温させることにより除去したりすることができる。その組み合わせは、自由に選択が可能である。
また、固形物の性状によっては酸性硫安を分解する温度域より高い温度が必要になる場合もあるが、このような場合は温度を高めて再生運転を行うことも可能である。
The internal combustion engine denitration apparatus according to the present embodiment includes regeneration heating means 41 and 42 for regenerating the catalyst of the downstream denitration catalyst unit 21 and the catalyst of the upstream denitration catalyst unit 22. As the regeneration heating means 41, 42, for example, a heater or a heating burner can be used, and the denitration catalyst is directly heated.
According to the present embodiment, the acidic ammonium sulfate and solid matter adhering to the downstream denitration catalyst unit 21 and the upstream denitration catalyst unit 22 can be decomposed and vaporized by the regeneration heating means 41 and 42.
Note that the regeneration heating means 41 may be provided only in the downstream denitration catalyst section 21, and conversely, the regeneration heating means 42 may be provided only in the upstream denitration catalyst section 22.
The heating burner 45 and the regeneration heating means 41 and 42 are operated during the operation of the internal combustion engine 11 to keep the temperature of the catalyst directly or indirectly high so that acidic ammonium sulfate or solid matter adheres to the catalyst. It can be suppressed or activated during a regeneration operation after the operation of the internal combustion engine 11 is stopped, and acid ammonium sulfate or solid matter adhering to the catalyst can be removed by raising the temperature. The combination can be freely selected.
Further, depending on the properties of the solid material, a temperature higher than the temperature range for decomposing acidic ammonium sulfate may be required. In such a case, it is possible to increase the temperature and perform the regeneration operation.
また本実施形態による内燃機関用脱硝装置は、上流側脱硝触媒部２２の上流側排気経路３２から分岐し、上流側脱硝触媒部２２の下流側で過給機１５の上流側排気経路３２に合流する脱硝バイパス経路３７と、脱硝バイパス経路３７を開閉する開閉手段３８を備えている。
本実施形態によれば、内燃機関１１の運転開始時に脱硝バイパス経路３７に排気ガスを流すことで内燃機関１１の動的特性の低下を防止することができる。
また本実施形態によれば、内燃機関１１の運転開始時や極低速運転時に開閉手段３８によって脱硝バイパス経路３７を開くことで内燃機関１１の効率低下を防止することができる。
Further, the internal combustion engine denitration apparatus according to the present embodiment branches from the upstream exhaust passage 32 of the upstream denitration catalyst portion 22 and joins the upstream exhaust passage 32 of the supercharger 15 on the downstream side of the upstream denitration catalyst portion 22. A denitration bypass path 37 for opening and opening / closing means 38 for opening and closing the denitration bypass path 37.
According to the present embodiment, it is possible to prevent the dynamic characteristics of the internal combustion engine 11 from being deteriorated by causing the exhaust gas to flow through the denitration bypass path 37 at the start of operation of the internal combustion engine 11.
Further, according to the present embodiment, the efficiency reduction of the internal combustion engine 11 can be prevented by opening the denitration bypass path 37 by the opening / closing means 38 at the start of operation of the internal combustion engine 11 or at an extremely low speed operation.
図２は本実施形態による内燃機関用脱硝装置の制御ブロック図である。
図１と同一構成部材には同一番号を付して説明を一部省略する。
本実施形態による内燃機関用脱硝装置は、給気経路１７に温度センサＴ１を、上流側排気経路３２の上流側脱硝触媒部２２より上流側に温度センサＴ２及び排気ガスセンサＧ１を、上流側排気経路３２の上流側脱硝触媒部２２より下流側に排気ガスセンサＧ２を、下流側排気経路３１の加熱バーナー４５より上流側に温度センサＴ３を、下流側排気経路３１の加熱バーナー４５より下流側に温度センサＴ４を、下流側排気経路３１の下流側脱硝触媒部２１より下流側に排気ガスセンサＧ３を、上流側脱硝触媒部２２の内部には温度センサＴ５を、下流側脱硝触媒部２１の内部には温度センサＴ６をそれぞれ設けている。
なお、図１では省略したが、上流側脱硝触媒部２２の流入側に開閉手段３８ａを設け、開閉手段３８を開放して脱硝バイパス経路３７に排気ガスを流す場合には開閉手段３８ａを閉塞する。
FIG. 2 is a control block diagram of the denitration device for an internal combustion engine according to the present embodiment.
The same constituent members as those in FIG.
The denitration device for an internal combustion engine according to the present embodiment includes the temperature sensor T1 in the air supply path 17, the temperature sensor T2 and the exhaust gas sensor G1 upstream of the upstream denitration catalyst portion 22 of the upstream exhaust path 32, and the upstream exhaust path. 32, an exhaust gas sensor G2 downstream from the upstream denitration catalyst section 22, a temperature sensor T3 upstream from the heating burner 45 in the downstream exhaust passage 31, and a temperature sensor downstream from the heating burner 45 in the downstream exhaust passage 31. T4 is an exhaust gas sensor G3 downstream of the downstream denitration catalyst portion 21 of the downstream exhaust passage 31, a temperature sensor T5 inside the upstream denitration catalyst portion 22, and a temperature inside the downstream denitration catalyst portion 21. A sensor T6 is provided.
Although not shown in FIG. 1, an opening / closing means 38 a is provided on the inflow side of the upstream side denitration catalyst unit 22, and when the opening / closing means 38 is opened and exhaust gas flows through the denitration bypass path 37, the opening / closing means 38 a is closed. .
制御器５１は、これらの温度センサＴ１、Ｔ２、Ｔ３、Ｔ４、Ｔ５、Ｔ６、及び排気ガスセンサＧ１、Ｇ２、Ｇ３からの検出信号を入力し、尿素水供給手段１６、開閉手段３８、３８ａ、再生用加熱手段４１、４２、排気ガス抽気手段４３、空気抽気手段４４、加熱バーナー４５、内燃機関１１を制御する負荷調整器５５に対して制御信号を出力する。
操作盤５２は、設定器５３と表示器５４を有し、設定器５３によって制御器５１での動作条件を設定し、表示器５４によって設定条件や動作状態を確認することができる。
本実施形態による内燃機関用脱硝装置の起動時には、制御器５１からの動作指令が負荷調整器５５に出力されて内燃機関１１の運転が開始される。この起動時には、制御器５１からの動作指令によって開閉手段３８を開、開閉手段３８ａを閉としている。
開閉手段３８が開、開閉手段３８ａが閉の状態で、温度センサＴ２からの検出信号と予め設定器５３で設定した所定温度との比較が制御器５１で行われ、温度センサＴ２での検出温度が設定温度を超えた場合には、制御器５１からの動作指令によって開閉手段３８を閉、開閉手段３８ａを開とする。
The controller 51 inputs detection signals from the temperature sensors T1, T2, T3, T4, T5, T6 and the exhaust gas sensors G1, G2, G3, the urea water supply means 16, the open / close means 38, 38a, the regeneration. A control signal is output to the heating means 41 and 42, the exhaust gas extraction means 43, the air extraction means 44, the heating burner 45, and the load regulator 55 that controls the internal combustion engine 11.
The operation panel 52 includes a setting device 53 and a display device 54. The operation device 52 can set operating conditions in the controller 51 with the setting device 53, and can check the setting conditions and the operating state with the display device 54.
When the denitration device for an internal combustion engine according to the present embodiment is started, an operation command from the controller 51 is output to the load regulator 55 and the operation of the internal combustion engine 11 is started. At the time of activation, the opening / closing means 38 is opened and the opening / closing means 38a is closed by an operation command from the controller 51.
With the opening / closing means 38 open and the opening / closing means 38a closed, the controller 51 compares the detection signal from the temperature sensor T2 with the predetermined temperature set in advance by the setting device 53, and the detected temperature at the temperature sensor T2 is detected. When the temperature exceeds the set temperature, the opening / closing means 38 is closed and the opening / closing means 38a is opened according to an operation command from the controller 51.
本実施形態による内燃機関用脱硝装置の定常運転時には、制御器５１から尿素水供給手段１６に対して動作指令が出されている。この定常運転時には、温度センサＴ２、Ｔ４で排気ガスの温度を監視するとともに、排気ガスセンサＧ１、Ｇ２、Ｇ３でＮＯｘの値を監視している。
定常運転時において、温度センサＴ２、Ｔ４での検出温度が所定温度よりも低い場合には、排気ガス抽気手段４３及び空気抽気手段４４の少なくとも一方を動作されることで排気ガス温度を上昇させる。
また、定常運転時において、温度センサＴ５での検出温度が所定温度よりも低い場合には、再生用加熱手段４２で上流側脱硝触媒部２２の温度を上昇させ、温度センサＴ６での検出温度が所定温度よりも低い場合には、再生用加熱手段４１で下流側脱硝触媒部２１の温度を上昇させる。
また、定常運転時において、温度センサＴ４での検出温度が所定温度よりも低く、温度センサＴ２での検出温度が所定温度以上保たれている場合には、加熱バーナー４５で下流側脱硝触媒部２１の温度を上昇させることもできる。
During the steady operation of the denitration device for an internal combustion engine according to the present embodiment, an operation command is issued from the controller 51 to the urea water supply means 16. During this steady operation, the temperature of the exhaust gas is monitored by the temperature sensors T2, T4, and the value of NOx is monitored by the exhaust gas sensors G1, G2, G3.
When the temperature detected by the temperature sensors T2 and T4 is lower than a predetermined temperature during steady operation, the exhaust gas temperature is raised by operating at least one of the exhaust gas extraction means 43 and the air extraction means 44.
Further, during the steady operation, when the temperature detected by the temperature sensor T5 is lower than the predetermined temperature, the temperature of the upstream denitration catalyst unit 22 is raised by the regeneration heating means 42, and the temperature detected by the temperature sensor T6 is increased. When the temperature is lower than the predetermined temperature, the temperature of the downstream side denitration catalyst unit 21 is raised by the regeneration heating means 41.
Further, during the steady operation, when the temperature detected by the temperature sensor T4 is lower than the predetermined temperature and the temperature detected by the temperature sensor T2 is maintained above the predetermined temperature, the downstream denitration catalyst unit 21 is heated by the heating burner 45. The temperature of the can also be raised.
また、定常運転時において、排気ガスセンサＧ１、Ｇ2、Ｇ3は、各部のＮＯｘ値を監視し、尿素水供給手段16の尿素水の噴射量や再生用加熱手段４１、４２、加熱バーナー４５、排気ガス抽気手段４３、空気抽気手段４４を適宜制御し、最終的に排気ガスセンサＧ3で検出されるＮＯｘ値を所定値以下に抑える。また、温度センサＴ2、Ｔ3、Ｔ４、Ｔ5、Ｔ6で検出される各部の温度を監視し、再生用加熱手段４１、４２、加熱バーナー４５、排気ガス抽気手段４３、空気抽気手段４４を適宜制御し、下流側脱硝触媒部２１、上流側脱硝触媒部２２に、酸性硫安や固形物が極力付着しないように温度制御を行う。
そして、排気ガスセンサＧ２と排気ガスセンサＧ１との差を制御器５１によって算出し、算出の結果上流側脱硝触媒部２２の劣化が検出された場合には、内燃機関11の運転中に、再生用加熱手段４２によって上流側脱硝触媒部２２を再生し、また、排気ガスセンサＧ３と排気ガスセンサＧ２との差を制御器５１によって算出し、算出の結果下流側脱硝触媒部２１の劣化が検出された場合には、再生用加熱手段４１によって下流側脱硝触媒部２１を再生する。また条件によっては、加熱バーナー４５によって例えば熱風を下流側排気経路３１に合流させ下流側脱硝触媒部２１を再生してもよい。
なお、この内燃機関11の運転中の再生運転は、排気ガスセンサＧ1、Ｇ2、Ｇ3の検出値に頼らずに、劣化予測時間に基づいて定期的に、再生用加熱手段４１、４２、加熱バーナー４５、排気ガス抽気手段４３、空気抽気手段４４を適宜制御し、下流側脱硝触媒部２１、上流側脱硝触媒部２２の温度を上げて、再生を行うことも可能である。
また、運転停止時においても、定期的に又は状況に応じて、再生用加熱手段４２によって上流側脱硝触媒部２２を再生し、また、再生用加熱手段４１、加熱バーナー４５によって下流側脱硝触媒部２１を再生することもできる。
Further, during steady operation, the exhaust gas sensors G1, G2, G3 monitor the NOx value of each part, and the urea water injection amount of the urea water supply means 16, the regeneration heating means 41, 42, the heating burner 45, the exhaust gas The extraction means 43 and the air extraction means 44 are appropriately controlled, and the NOx value finally detected by the exhaust gas sensor G3 is suppressed to a predetermined value or less. Further, the temperature of each part detected by the temperature sensors T2, T3, T4, T5, and T6 is monitored, and the regeneration heating means 41 and 42, the heating burner 45, the exhaust gas extraction means 43, and the air extraction means 44 are appropriately controlled. Then, temperature control is performed so that acidic ammonium sulfate and solid matter do not adhere to the downstream side denitration catalyst unit 21 and the upstream side denitration catalyst unit 22 as much as possible.
Then, the difference between the exhaust gas sensor G2 and the exhaust gas sensor G1 is calculated by the controller 51. When the deterioration of the upstream denitration catalyst unit 22 is detected as a result of the calculation, the regeneration heating is performed during the operation of the internal combustion engine 11. When the upstream side denitration catalyst unit 22 is regenerated by the means 42, and the difference between the exhaust gas sensor G3 and the exhaust gas sensor G2 is calculated by the controller 51. As a result of the calculation, deterioration of the downstream side denitration catalyst unit 21 is detected. Regenerates the downstream denitration catalyst section 21 by the regeneration heating means 41. Further, depending on conditions, the downstream denitration catalyst unit 21 may be regenerated by, for example, hot air joining the downstream exhaust passage 31 by the heating burner 45.
Note that the regeneration operation during the operation of the internal combustion engine 11 does not depend on the detection values of the exhaust gas sensors G1, G2, and G3, but periodically based on the estimated deterioration time, the regeneration heating means 41 and 42, and the heating burner 45. It is also possible to perform regeneration by appropriately controlling the exhaust gas extraction means 43 and the air extraction means 44 to raise the temperatures of the downstream denitration catalyst section 21 and the upstream denitration catalyst section 22.
Even when the operation is stopped, the upstream side denitration catalyst unit 22 is regenerated by the regeneration heating means 42 periodically or according to the situation, and the downstream side denitration catalyst unit is regenerated by the regeneration heating means 41 and the heating burner 45. 21 can also be reproduced.
図３は本実施形態による内燃機関用脱硝装置を搭載した船舶を示す構成図である。
同図に示すように、船舶６０には、本実施形態による内燃機関用脱硝装置が搭載され、プロペラは内燃機関１１によって回転し、下流側脱硝触媒部２１を通過した排気ガスは、煙突６１から大気に放出される。
また、空気抽気手段４４から取り出した空気は、例えば船舶６０の前方船体下部の噴出口４４ａから噴出させることで、船体の抵抗を減じる手段として利用したり、ブロワーを介した発電機での発電に利用することができる。
また、図示はしないが、排気ガス抽気手段４３から取り出した排気ガスは、ボイラーやタービンに利用することができる。
本実施形態によれば、毒性が高く取り扱いが困難なアンモニアではなく、尿素水を還元剤として用いるために、船舶６０でも安全に取り扱うことができる。
FIG. 3 is a block diagram showing a ship equipped with a denitration device for an internal combustion engine according to the present embodiment.
As shown in the figure, the ship 60 is equipped with the denitration device for an internal combustion engine according to the present embodiment, the propeller is rotated by the internal combustion engine 11, and the exhaust gas that has passed through the downstream denitration catalyst portion 21 is sent from the chimney 61. Released into the atmosphere.
Further, the air taken out from the air extraction means 44 is used as means for reducing the resistance of the hull by, for example, being jetted from the jet outlet 44a at the lower front hull of the ship 60, or for generating power with a generator via a blower. Can be used.
Although not shown, the exhaust gas extracted from the exhaust gas extraction means 43 can be used for a boiler or a turbine.
According to the present embodiment, since the urea water is used as the reducing agent instead of ammonia which is highly toxic and difficult to handle, the ship 60 can be handled safely.
本発明は、船用大型低速ディーゼル機関以外にも陸上発電用の大型低速ディーゼル機関や、排気ガス温度の低い中速ディーゼル機関にも適用できる。 The present invention can be applied to a large-scale low-speed diesel engine for onshore power generation and a medium-speed diesel engine having a low exhaust gas temperature in addition to a large-scale low-speed diesel engine for ships.
１１ 内燃機関
１２ 排気レシーバ
１３ タービン
１４ コンプレッサー
１５ 過給機
１６ 尿素水供給手段
１７ 給気経路
２１ 下流側脱硝触媒部
２２ 上流側脱硝触媒部
３１ 下流側排気経路
３２ 上流側排気経路
３７ 脱硝バイパス経路
３８ 開閉手段
４１ 再生用加熱手段
４２ 再生用加熱手段
４３ 排気ガス抽気手段
４４ 空気抽気手段
４５ 加熱バーナー
６０ 船舶
DESCRIPTION OF SYMBOLS 11 Internal combustion engine 12 Exhaust receiver 13 Turbine 14 Compressor 15 Supercharger 16 Urea water supply means 17 Air supply path 21 Downstream side denitration catalyst part 22 Upstream side denitration catalyst part 31 Downstream side exhaust path 32 Upstream exhaust path 37 Denitration bypass path 38 Opening / closing means 41 Regeneration heating means 42 Regeneration heating means 43 Exhaust gas extraction means 44 Air extraction means 45 Heating burner 60 Ship
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| JP5295403B2 (en) * | 2012-03-02 | 2013-09-18 | 日立造船株式会社 | Marine exhaust gas denitration reactor and exhaust gas denitration equipment |
| KR101236305B1 (en) * | 2012-05-24 | 2013-02-22 | 주식회사 덱코 | Apparatus for removing nitrogen oxides and method for removing nitrogen oxides thereof |
| JP5539461B2 (en) * | 2012-08-03 | 2014-07-02 | 日立造船株式会社 | Exhaust gas denitration equipment for reciprocating engines |
| DE102012019947A1 (en) * | 2012-10-11 | 2014-04-17 | Man Diesel & Turbo Se | Internal combustion engine |
| JP6655241B2 (en) * | 2015-06-19 | 2020-02-26 | 国立研究開発法人 海上・港湾・航空技術研究所 | Denitrification desulfurization apparatus and land and ship internal combustion engine using the same |
| JP2018184842A (en) * | 2017-04-24 | 2018-11-22 | ボルカノ株式会社 | Heated gas generator for internal combustion engine denitration device and method for operating the same |
| EP3670855A1 (en) * | 2018-12-19 | 2020-06-24 | Winterthur Gas & Diesel Ltd. | Exhaust gas aftertreatment system |
| CN115711167A (en) * | 2022-10-28 | 2023-02-24 | 重庆交通大学 | Exhaust gas temperature compensation device of ship low-pressure SCR system |
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| JPH0658058B2 (en) * | 1990-03-13 | 1994-08-03 | ダイハツデイーゼル株式会社 | Diesel engine |
| JPH0544224U (en) * | 1991-11-15 | 1993-06-15 | 三菱重工業株式会社 | Denitration equipment |
| JPH06235319A (en) * | 1993-02-05 | 1994-08-23 | Yanmar Diesel Engine Co Ltd | Internal combustion engine equipped with reduced type denitration catalyst |
| JP3735169B2 (en) * | 1996-11-29 | 2006-01-18 | 三菱重工業株式会社 | Diesel engine with denitration equipment |
| JP3876705B2 (en) * | 2001-12-13 | 2007-02-07 | いすゞ自動車株式会社 | Diesel engine exhaust gas purification system |
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